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Photonics
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Photonics is the science of generating, controlling, and detecting photons. This is particularly done in the visible and near-infrared spectrums of the electromagnetic spectrum but may also extend to the ultraviolet (0.2–0.35 µm wavelength), long-wave infrared (8–12 µm wavelength), and far-infrared/THz (e.g., 2-4 THz corresponding to 75–150 µm wavelength) portions of the spectrum.
Photonics developed as an outgrowth of the first practical semiconductor light emitters invented in the early 1960s and optical fibers developed in the 1970s.
science of photonics includes investigation of the emission, transmission, amplification, detection, and modulation of light.
Amongst the light sources, we do not find in particular devices such as incandescent or fluorescent lightbulbs, but more commonly light-emitting diodes and lasers, particularly semiconductor lasers.
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Photonics is the science of generating, controlling, and detecting photons. This is particularly done in the visible and near-infrared spectrums of the electromagnetic spectrum but may also extend to the ultraviolet (0.2–0.35 µm wavelength), long-wave infrared (8–12 µm wavelength), and far-infrared/THz (e.g., 2-4 THz corresponding to 75–150 µm wavelength) portions of the spectrum.
Photonics developed as an outgrowth of the first practical semiconductor light emitters invented in the early 1960s and optical fibers developed in the 1970s.
Overview of photonics research
The science of photonics includes investigation of the emission, transmission, amplification, detection, and modulation of light.
Amongst the light sources, we do not find in particular devices such as incandescent or fluorescent lightbulbs, but more commonly light-emitting diodes and lasers, particularly semiconductor lasers. Plasma screens, cathode ray tubes, TFT screens and LCD screens are also among them. With the detectors, we find classical thermic sensors and videcons, but particularly charged coupled device cameras and photodiodes.
Photonic devices include optoelectronic devices such as lasers and photodetectors, as well as optical fiber and planar waveguides, and waveguide-based passive devices.
Charisteristical for photonics is the frequent use of 3-5 and 2-6 semiconductors instead of the classical silicon (and germanium). Silicon and germanium are in group 4 of the periodic table. Photonics thus uses compounds as gallium arsenide (GaAs) and aluminium gallium arsenide (AlGaAs).
The most advanced area of photonic research is fabrication and investigation of special structures and "materials" with engineered optical properties. These include photonic crystals, photonic crystal fibers and metamaterials.
History of photonics
The word 'Photonics' appeared in the late 1960s to describe a research field whose goal was to use light to perform functions that traditionally fell within the typical domain of electronics, such as telecommunications, information processing, etc.
Photonics as a field really began in 1960, with the invention of the laser, and the laser diode followed in the 1970s by the development of optical fibers as a medium for transmitting information using light beams, and the Erbium-doped fiber amplifier. These inventions formed the basis for the telecommunications revolution of the late 20th century and provided the infrastructure for the internet.
Historically, the term photonics only came into common use among the scientific community in the 1980s as fiber optic transmission of electronic data was adopted widely by telecommunications network operators (although it had earlier been coined). At that time, the term was adopted widely within Bell Laboratories. Its use was confirmed when the IEEE Lasers and Electro-Optics Society established an archival journal named Photonics Technology Letters at the end of the 1980s.
During the period leading up to the dot-com crash circa 2001, photonics as a field was largely focused on telecommunications. However, photonics covers a huge range of science and technology applications, including: Laser manufacturing, Biological and chemical sensing, Medical diagnostics and therapy, Display technology, Optical computing.
Various non-telecom photonics applications exhibit a strong growth particularly since the dot-com crash, partly because many companies have been looking for new application areas quite successfully. A huge further growth of photonics can be expected for the case that the current development of silicon photonics will be successful.
Relationship to other fields
Classical optics
Photonics is closely related to optics. However optics preceded the discovery that light is quantized (when the photoelectric effect was explained by Albert Einstein in 1905). The tools of optics are the refracting lens, the reflecting mirror, and various optical components which were known prior to 1900. The key tenets of classical optics, such as Huygens Principle, the Maxwell Equations, and wave equations, do not depend on quantum properties of light.
Modern optics
Photonics is approximately synonymous with quantum optics, quantum electronics, electro-optics, and optoelectronics. However each is used with slightly different connotations by scientific and government communities and in the marketplace. Quantum optics often connotes fundamental research, whereas photonics is used to connote applied research and development.
The term photonics more specifically connotes:
- the particle properties of light,
- the potential of creating signal processing device technologies using photons,
- those quantum optical technologies which are manufacturable and can be low-cost, and
- an analogy to electronics.
The term optoelectronics eponymously connotes devices or circuits comprising both electrical and optical functions, i.e., a thin-film semiconductor device. The term electro-optics came into earlier use and specifically encompasses nonlinear electrical-optical interactions applied, e.g, as bulk crystal modulators such as the Pockels cell, but also includes advanced imaging sensors typically used for surveillance by civilian or government organizations.
Emerging fields
Photonics also relates to the emerging science of quantum information in those cases where it employs photonic methods. Other emerging fields include opto-atomics in which devices integrate both photonic and atomic devices for applications such as precision timekeeping, navigation, and metrology. Another emerging field is polaritonics which differs with photonics in that the fundamental information carrier is a phonon-polariton, which is a mixture of photons and phonons, and operates in the range of frequencies from 300 gigahertz to approximately 10 terahertz.
Applications
Applications of photonics are ubiquitous. Included are all areas from a common live to the most advanced science, e.g. light detection, telecommunications, information processing, illumination, metrology, spectroscopy, holography, medicine (surgery, vision correction, endoscopy, health monitoring), military technology, laser material processing, visual art, biophotonics, agriculture, and robotics.
Just as applications of electronics have expanded dramatically since the first transistor was invented in 1948, the unique applications of photonics continue to emerge. Those which are established as economically important applications for semiconductor photonic devices include optical data recording, fiber optic telecommunications, laser printing (based on xerography), displays, and optical pumping of high-power lasers. The potential applications of photonics are virtually unlimited and include chemical synthesis, medical diagnostics, on-chip data communication, laser defense, and fusion energy, to name several interesting additional examples.
- Consumer equipment: Barcode scanner, printer, CD/DVD/Blu-ray devices, remote control devices
- Telecommunications: Optical fiber communications, Optical Down converter to Microwave
- Medicine: Correction of poor eyesight, laser surgery, surgical endoscopy, tattoo removal
- Industrial manufacturing: The use of lasers for welding, drilling, cutting, and various methods of surface modification
- Construction: Laser leveling, laser rangefinding, smart structures
- Aviation: photonic gyroscopes lacking mobile parts
- Military: IR sensors, command and control, navigation, search and rescue, mine laying and detection
- Entertainment: Laser shows, beam effects, holographic art
- Information processing
- Metrology: Time and frequency measurements, rangefinding
- Photonic computing: clock distribution and communication between computers, circuit boards, or within optoelectronic integrated circuits; in the future: quantum computing
See also
Sources
External links
General
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- - Optical Society of America
- The Internet Portal of the Dutch Photonics Society
Periodicals
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